Perishable or environmentally sensitive goods risk damage from numerous sources such as wind, dirt, heat, insects, etc. during transportation. Various forms of packaging have been used to minimize damage or decay of such goods. For example, goods are often secured to a pallet to facilitate the transport of such goods and to protect the goods from damage caused by shifting during transport. In order to further protect and preserve the goods during transport, it is well known to cover the goods so as to form an enclosure around the goods. Known techniques to create an enclosure include heat shrinking plastic around the goods which has been placed on a pallet or placing a plastic bag around the goods on a pallet. By forming such an enclosure, referred to as a "sealed enclosure" herein, the goods can be protected from environmental factors such as moisture or other contaminants. The more airtight the sealed enclosure, the better the sealed enclosure protects the goods from external contaminants.
FIG. 1 shows a well-known apparatus 50 for storing goods during transport. The apparatus 50 includes a base cap 10 positioned over a pallet 30. After the base cap 10 is positioned on the pallet 30, the base cap 10 is usually held in place by the goods 40 that are stacked on top of the base cap 10. The base cap 10 further includes side flaps or walls 12 which extend upwardly from the peripheral edges of the base cap 10, for surrounding and holding the goods 40 within their boundaries. Typically, the goods 40 are then further secured to the base cap 10 and the pallet 30 with staples or some type of tape that wraps around the goods 40 and the base cap 10.
The base cap 10 forms a barrier between the goods 40 and the pallet 30 and is typically made from some type of plastic, relatively impermeable material shaped to fit over the pallet 30. The base cap 10 seals and protects the bottom surface of the goods 40 from contamination and also provides a surface to which the goods 40 can be secured. The base cap 10 can be any shape or material, but is preferably sized to cover the pallet 30 and preferably made of a relatively water and gas impermeable material to form a seal barrier at the underside of the goods 40. Goods 40 are stacked on the base cap 10 which is placed on top of the pallet 30. The goods 40 can be a variety of types or sizes and preferably are in boxes or containers. While three layers of boxed goods 40 are shown, there can be more or less layers. The combination of stacked goods 40 on the base cap 10 and the pallet 30, as illustrated in FIG. 1, is referred to herein as the loaded pallet 50.
FIG. 2 illustrates a well-known method of creating a sealed enclosure around the loaded pallet 50 of FIG. 1. A bag-like covering 90 is placed around the goods 40 and secured to the base cap 10 of the loaded pallet 50, thereby forming a sealed enclosure around the goods 40. Preferably, the bag covering 90 is adhered to the base cap 10 and the pallet 30 with tape, or other well-known technique, to create an airtight seal.
Prior art enclosure systems, such as those discussed above, suffer from many disadvantages. Using a bag covering 90 to form the enclosure, as shown in FIG. 2, is disadvantageous in that it is difficult to seal the bottom end of the cover 90 with the base cap 10. The bag covering 90 is often larger than the base cap 10, so sealing the bag covering 90 to the base cap 10 requires folding and creasing of the bag covering 90. The folding and creasing of the bag covering 90 to fit the base cap 10 prevents a smooth contact between the inside surface of the bag covering 90 and outside edges of the base cap 10. Furthermore, the folds and creases form possible gaps or channels for gases to bypass the seal, thus, preventing an airtight enclosure.
Likewise, when wrapping plastic around palletized goods, it is difficult to completely seal the enclosure, especially at the top and bottom sides. The wrapping must curve around the corners and edges of goods 40, leading to potential gaps or creases in the wrapping. As previously discussed, the gaps and creases are undesirable in that they provide possible channels for air to escape or enter the sealed enclosure.
After the goods 40 have been loaded onto the pallet 30 and sealed by some method, such as by covering 90 and base cap 10 as described above, the goods 40 can be further protected and preserved by providing a modified atmosphere inside the enclosure surrounding the goods 40. For example, it is well known to inject gases such as nitrogen and carbon dioxide within the enclosure in order to deter deterioration of the goods, for example, by the growth of organisms that may contribute to the natural deterioration of produce. Other mixtures of gases can help maintain the goods 40 if held at an appropriate temperature and humidity.
Good sealed enclosures are especially important in these modified air systems. If the sealed enclosure leaks, the beneficial gases may escape. Furthermore, a change in the composition of gases in the enclosure may damage the goods. For example, an excessive amount of CO.sub.2 in the enclosure may cause food to discolor and to change taste.
The predominant present technique for introducing the modified atmosphere into the sealed enclosure is to inject the gas mixture through a needle-tipped hose. The needle-tipped hose is inserted through the covering of a sealed enclosure (such as bag covering 90 in FIG. 2). The needle-tipped hose is then taped to the covering and a desired gas mixture is injected through the hose into the sealed enclosure. The process ends by removal of the needle-tipped hose from the enclosure and re-sealing of the resulting hole in the covering with tape or other adhesive.
This present system for introducing the modified atmosphere into the sealed enclosure is disadvantageous. The steps of manually piercing the enclosure to insert the needle hose and resealing the resulting hole are labor extensive, adding cost and delays to the shipping process. The process of piercing and resealing the enclosure is also undesirable in that it may create a potential leak in the enclosure. The tape or adhesive may not seal properly, creating leaks in the sealed enclosure.
Another disadvantage of the present enclosed pallet transport systems is that they do not allow the user to monitor and adjust the atmosphere within the sealed enclosure during storage or transport. A typical result of this shortcoming is that the atmosphere deteriorates during storage or transport. For example, respiration of produce will accelerate the ripening and aging of produce during transport and will change the quality of the gases in the enclosure. As a result, the goods may deteriorate during transport, especially if delayed by unforeseen circumstances.
Furthermore, the transporter cannot adjust the atmosphere to accommodate a good with varying needs. For example, the ripening of fruits is generally undesirable during transport and storage but may be desirable as the fruits near their final markets. It is well known that certain combinations of gases prevent the ripening of fruits while others encourage the fruits to ripen. Thus it is desirable to have the enclosure containing the former gas mixture during most of transport, but changing to the latter gas mixture as the fruits near their final markets.
It is also known to be beneficial to provide a controlled environment around the goods 40 during transportation and storage. For example, the goods 40 can be transported in refrigerated trucks, ships, or railcars. Within the cargo holding area of specialized transport vehicles, the temperature or atmospheric contents around the goods can be adjusted and controlled during transport. However, transportation of goods by these environment controlling vehicles has several problems. Foremost, most transport vehicles do not have the ability control the atmospheric environment of the cargo holding area. For example, most trucks have the capacity to only maintain the cool temperature of their cargo. Environmental control requires additional specialized equipment and this specialized equipment significantly raises the costs for the transport vehicle, ship, or storage facility. As a result, there are not enough environment controlling vehicles to transport goods. Transportation of a larger range of goods in controlled environments could provide significant benefits to the consumer by reducing loss of goods during transport
A further disadvantage of current vehicles having a combined temperature and controlled atmosphere enclosure is the dehydration of products during storage (due to evaporation through cooling). Much energy is required to cool a large enclosure. The energy consumption raises fuel and transportation costs.
Thus, in view of the deficiencies and problems associated with prior art methods and systems for storing and transporting perishable or environment-sensitive goods, an improved method and system of transporting such goods is needed. A method and system for more easily and efficiently creating a sealed enclosure around the perishable goods is desired. What is further needed is a method and system which can provide, monitor and/or maintain a controlled environment within the sealed enclosure of a standard pallet, bin or other shipping unit without the use of expensive, specialized vehicles having atmosphere-controlled cargo holds, such as ships, specialized sea containers, and refrigerated trucks, for example.